ALL IN THE HEAD
NEURORADIOLOGY AND NEUROIMAGING : A BRIEF HISTORY AND MY 32-YEAR EXPERIENCE
AUTHOR J . Tim Burger , MD
Since I started my residency in 1983 , there have been many advancements in imaging of the central nervous system ( CNS ). Indirect depiction of CNS structures has been replaced with direct visualization of the brain , spinal cord and nerves . Purely anatomic studies have been supplemented with functional , physiologic and occasionally molecular imaging . Noninvasive techniques , constantly evolving , have significantly reduced our use of invasive studies , avoiding their inherent risks and potential complications . Contrast materials change , and their safety profiles are improved . Access to computed tomography ( CT ) and magnetic resonance imaging ( MRI ) is now available at even more remote hospitals . Advancements in computers , the internet , digital imaging , picture archiving and communication systems ( PACS ) and teleradiology have also positively impacted patient care . I will give a brief review of the early history and my more than 32 years of experience in neuroimaging .
Perhaps neuroradiology began after skull X-rays were obtained following the discovery of X-rays by Wilhelm Roentgen on Nov . 8 , 1895 . Plain films were followed by ventriculography in 1918 and pneumoencephalography in 1919 , developed by neurosurgeon
Walter E Dandy . Air was injected directly into the ventricles or into the spinal canal after the cerebrospinal fluid ( CSF ) had been drained . ( Image 1 ) Positive contrast myelography started in 1921 , and cerebral angiography in 1927 by the Portuguese neurologist Egas Moniz . In 1953 , the Swedish radiologist Sven Seldinger developed the catheter over guide wire technique which significantly improved the safety of cerebral and other angiographic techniques . However , all of the above indirect x-ray procedures relied on the displacement of neural structures with positive or negative contrast . It would take almost 20 years for the next frontier to be reached : direct imaging of the CNS . 1
The first commercially available CT scanner , made by Sir Godfrey Hounsfield , was installed in the United Kingdom in 1971 . The first CT scanners in the US were installed in 1973 , initially designed for imaging of the head . This was a quantum leap in neuroradiology . ( Image 2 ) For the first time , noninvasive imaging of the brain could be obtained . X-rays could differentiate bone , soft tissue , fat and air . CT could delineate calvarium , brain , gray matter , white matter and cerebrospinal fluid and ultimately pathologic hemorrhage , calcification and edema . For almost 50 years , head CT has been the primary neuroradiologic diagnostic tool for significant head trauma , acute onset severe headache , acute change in mental status and stroke
6 LOUISVILLE MEDICINE